The 2015 MBP is a work horse but it too had issues with external monitors. I used to connect it to two external 1080p monitors one via HDMI the other with some

The 2015 MBP is a work horse but it too had issues with external monitors. I used to connect it to two external 1080p monitors one via HDMI the other with some ancient adapter. When I plugged in the latter my internet would suddenly stop working. This was apparently from a multi year bug where the ports adapter was so close to the wireless card that it interfered with the wireless cards normal operation. Upgrading the adapter fixed the problem (it was one of the old display adapters with physical pins you had to screw in) - took a very long time to debug that issue!